The owner or contractor of any building in course of erections or removal must provide toilet accommodations for the workmen.  The toilet must be connected with the sewer just inside the pavement wall, supplied with water, and kept clean.  In case it is impossible to connect with a sewer for lack of a sewer in the street or alley, then the owner or contractor shall provide a temporary vault not less than 6 feet deep.  The vault must be disinfected each day by covering the contents to a depth of not less than 3 inches with fresh earth and air slacked lime.  On completion of the work, the vault shall be removed and the premises left in a sanitary condition.  The use of such a vault shall not exceed 90 days on any premises.